Cellular phones, which correspond to a type of portable terminals, are widely used as one of personal communication means by which a user may perform voice communication and wireless communication while carrying them. In recent years, smartphones, tablet PCs, and the like, which are intelligent terminals that may perform Internet communication and a computer support function in addition to voice communication, have been mainly utilized.
Meanwhile, it is general for the user to use a portable terminal while gripping it. However, because a portable terminal, such as a smartphone, has a large width due to the large screen thereof, a user having a small hand may have a difficulty in manipulating the portable terminal while gripping it. When the user miss the portable terminal from the hand or accidentally collides with another person and drops the portable terminal while using it, the portable terminal may be damaged or broken down.